1. Field of the Invention
The invention relates to a shift lever lock device for vehicular automatic transmission in which a solenoidal coil is energized to produce a magnetic attraction upon unlocking a shift lever.
2. Description of Prior Art
In a shift lever lock device which is mounted on a vehicular automatic transmission, a locking mechanism is provided to effectuate a reverse shift lock and a parking shift lock to insure a safety on navigation by utilizing an electronic solenoid. The reverse shift lock prevents the shift lever from inadvertently moving toward R-range position so as to eliminate a reverse shift shock when the navigating the vehicle at the speed exceeding a predetermined limit.
The parking shift lock prevents the shift lever from inadvertently moving toward D-range position from P-range position once a vehicle is parked with the shift lever located in P-range position.
Upon actuating an ignition key, applying a foot brake permits to release the shift lever so as to render the shift lever operable toward D-range position from P-range position, thus preventing the vehicle from abruptly moving forward due to the inadvertent shifting operation toward D-range position.
Upon releasing the shift lever from the locked position, laterally operating the shift lever makes it operable for a gate type or column type shift lever. For a release button type shift lever, pushing a release button on a knob of the shift lever permits it operable. Upon operating the shift lever to P-range position at the time of parking the vehicle, the shifting operation makes a locker pin move to the locked position so as to render the release button inoperable. Applying the foot brake energizes the electronic solenoid to move the locker pin to an unlocked position from the locked position so as to render the release button operable.
By way of illustration, Japanese Laid-open Patent Application No. 2002-362179 discloses a shift lever device for vehicular automatic transmission. The shift lever device has a rotary shaft to which a follower and a stopper are rockably attached. A metallic plate is placed to stick to a magnet metal with the shift lever stayed in the locked position.
Upon unlocking the shift lever, the metallic plate rotationally moves in the predetermined direction with the metallic plate stuck to the magnet metal. This apparently prevents the metallic plate from hitting against the magnet metal with no operational noise induced since the metallic plate does not encounter the magnet metal when it rotationally moves in the predetermined direction.
However, the magnet metal is mounted on the middle of the follower, thus making the follower lengthened in its axial direction so as to occupy a larger space, which deters the device from providing a space-saving structure with it. The magnet metal adds its weight to the follower so as to make it difficult to provide a smooth and quick rotary movement with the follower when the follower rotationally moves in the predetermined direction.
Since the magnet metal rotationally moves in unison with the follower, electric lead wires extended from the magnet metal to a power source is subjected to repetitive deformation due to an exterior force appeared when the magnet metal moves.
The repetitive deformation subjected to electric lead wires may give the lead wires fatigues resulting them in disconnection at the worst case. A reactionary force appeared when the electric lead wires deform, further deters from imparting a smooth and quick rotary movement to the follower when the follower rotationally moves in the predetermined direction.
Therefore, the present invention has been made with the above drawbacks in mind, it is a primary object of the invention to provide a shift lever lock device for vehicular automatic transmission which is capable of making a lock plate and a link plate dimensionally shortened in their axial direction so as to make them advantageous from the space-saving point of view, and enabling both the plates to a smooth and quick rotational movement without inviting operational noise when unlocking a shift lever by energizing a solenoidal coil.
It is a secondary object of the invention to provide a shift lever lock device for vehicular automatic transmission which is capable of making electric lead wires of a solenoidal coil free from disconnection with no fatigues rested on the electric lead wires, and contributing to imparting a smooth and quick rotary movement to a lock plate and a link plate without inviting a reactionary force on the electric lead wires when the lock plate and the link plate rotationally move.
It is a tertiary object of the invention to provide a shift lever lock device for vehicular automatic transmission which is capable of reducing an urging force of an urging member exerting toward a link plate, thus mitigating click noise induced when the link plate returns to an original position.